The concept of wormholes, which are hypothetical structures connecting two distant points in spacetime, is still largely speculative and remains an area of active scientific research. As such, our understanding of wormholes is limited, and there is no definitive answer to when a wormhole would cease to exist.
One possibility is that a wormhole would collapse or destabilize due to various factors, such as the properties of matter passing through it or the influence of external forces. For instance, the extreme conditions within a wormhole, such as high energy densities or tidal forces, might cause it to collapse or become unstable.
Additionally, the properties of exotic matter, which is often theorized to be necessary to sustain a wormhole, could play a role. Exotic matter, characterized by negative energy density or negative mass, is purely hypothetical and has not been observed or confirmed to exist. The behavior and stability of wormholes would depend on the properties and behavior of such exotic matter.
Ultimately, since our current understanding of the physics of wormholes is incomplete, it is challenging to provide a definitive answer regarding their lifespan or cessation. Continued scientific research and advances in theoretical physics may shed more light on this topic in the future.